Asteroid 2024 YR4 had everyone collectively holding their breath just months ago, but now, it appears that the city-killer asteroid has a stronger chance of striking the Moon, not Earth. The asteroid currently has a 3.8 percent chance to hit the Moon on December 22, 2032, according to the latest announcement from NASA.Ongoing infrared observations by the James Webb Space Telescope (JWST) have continued to unveil more precise information about 2024 YR4 and its potential trajectory throughout space, yet the asteroids ultimate fate is far from being set in stone.Asteroid 2024 YR4's New Potential Target2024 YR4 initially caused a commotion earlier in 2025 as its chances of colliding with Earth in 2032 gradually increased. The impact probability with Earth bumped up from around 1 percent in late January to around 3 percent in February, but it has since slumped to only 0.004 percent. Scientists saw the probability plunge coming since similar trends have been observed with previous asteroids, and theyre now reassuring the public that 2024 YR4 poses no significant threat to our planet.Although Earth is in the clear, the Moon may not be so lucky. NASA announced in late February that the asteroids estimated trajectory had moved farther from Earth, but also that there would still be a 1.7 percent chance for it to impact the Moon. New observations have raised the lunar impact probability to 3.8 percent (but there is a 96.2 percent chance that the asteroid will entirely miss the Moon).Not only that, but scientists now have a better idea of how large 2024 YR4 is. They originally thought the size would be somewhere from 40 meters to 90 meters (131 feet to 295 feet), but theyve now narrowed the estimate down to 53 meters to 67 meters (174 feet to 220 feet). For reference, that means the asteroid would be roughly the same size as a 10-story building.Asteroid Impacts on the MoonThe fearsome reputation of 2024 YR gained so much interest in the first place because it was believed that if the asteroid were to hit Earth, it would cause major destruction to a city. Earths cities dont need to worry anymore, but what happens if the city-killer strikes the Moon?First and foremost, NASA clarified in their announcement that a lunar collision would not alter the Moons orbit. The Moon would instead simply be left with another crater; yet, if a collision did occur, it would give scientists an unprecedented opportunity to study a live impact of such substantial size.The Moon already contains hundreds of thousands or even millions of craters that vary in size, most of them originating from ancient asteroid impacts. Though lunar impacts have become less frequent over time, tiny meteoroids still create dents in the Moon every day. An impact from a larger asteroid like 2024 YR4 would likely create a bright flash and send debris into space; most pieces of Moon rock would then burn up in the Earths atmosphere.Earth's Defenses Against AsteroidsAlthough planetary defense measures aren't needed to protect Earth from 2024 YR4, scientists have been interested in developing ways to detect hazardous asteroids and deflect them if ever needed.In 2022, NASA successfully altered the orbit of a target asteroid, Dimorphos, through its Double Asteroid Reflection Test (DART) mission. Dimorphos wasn't headed for a dangerous collision with Earth, but it was an ideal target to test a deflection plan that involved crashing a spacecraft into it.Launching in 2027, another NASA spacecraft called the NEO Surveyor will be able to spot asteroids and comets (together known as near-earth objects, or NEOs) that come within 30 million miles of Earths orbit. As for 2024 YR4, scientists will get another look at the asteroid in late April or early May once the JWST makes its next observations. Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:The Planetary Society. What would happen if an asteroid hit the Moon?NASA. Lunar Impact VideosJack Knudson is an assistant editor at Discover with a strong interest in environmental science and history. Before joining Discover in 2023, he studied journalism at the Scripps College of Communication at Ohio University and previously interned at Recycling Today magazine.